Are you really? It's a pretty ridiculous concept that would only appeal to an obvious minority. And it doesn't have any "moe" like Qwaser and other high school themed echi that would attract that type of audience. It did pretty decent I'd say.

Hyakka Ryouran SAMURAI GIRLS, the various Ikkitousen and Freezing have all done well recently with a similar concept of fights and big boobs.